Nanostructured Ti-Ta thin films synthesized by combinatorial glancing angle sputter deposition

Area of Science:

• Materials Science
• Nanotechnology
• Thin Film Deposition

Background:

• Titanium-tantalum (Ti-Ta) alloys are promising for actuators and biomedical implants due to their unique properties.
• Thin film fabrication is crucial for micro-actuators, micro-implantable devices, and surgical implant coatings.
• Nanostructured materials offer enhanced properties compared to bulk counterparts.

Purpose of the Study:

• To fabricate and characterize Ti-Ta nanocolumnar thin films using glancing angle deposition (GLAD).
• To investigate the influence of substrate pre-patterning and combinatorial deposition on nanostructure formation.
• To explore the potential of these films for advanced applications.

Main Methods:

• Fabrication of Ti_100-xTa_x (x = 21, 30) nanocolumnar thin films via GLAD at room temperature.
• Characterization of crystal structure, morphology, and microstructure using XRD, SEM, and TEM.
• Utilizing laser pre-patterned substrates and a combinatorial-GLAD approach for controlled nanostructure and composition variations.

Main Results:

• Perpendicularly oriented nanocolumns (∼150-160 nm width) were formed for both Ti₇₉Ta₂₁ and Ti₇₀Ta₃₀ compositions.
• A disordered α″ martensite phase with orthorhombic structure was observed in as-deposited films.
• Periodic nanocolumnar arrays and multi-level porous nanostructures were achieved using pre-patterned substrates; a composition spread from Ti_72.8Ta_27.2 to Ti_64.4Ta_35.6 was created.

Conclusions:

• GLAD, substrate pre-patterning, and combinatorial approaches are effective for fabricating Ti-Ta nanocolumnar thin films.
• The nanostructuring methods offer a promising route for investigating Ti-Ta films for diverse applications.
• These techniques can be adapted for other material systems requiring nanocolumnar morphology.